witching hour (idea)

If a job is scheduled during the 'witching hour' - the time during a change from the main to alternate time zone, the job will either be run once (if the actual time exists twice) or not at all (if the actual time never exists).

If my hazy memory is correct, the Unix guys used to call and the hour that never happens (spring forward) the 'devils hour', and the hour that happens twice (spring forward, fall back) the 'witching hour'.

Of course, neither of these have anything to do with the Pagan/Wiccan tradition of the witching hour, which is typically midnight every night.